Shabani Sadegh, White Jonathan M, Hutton Craig A
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute , The University of Melbourne , Melbourne , Victoria 3010 , Australia.
Org Lett. 2019 Mar 15;21(6):1877-1880. doi: 10.1021/acs.orglett.9b00488. Epub 2019 Mar 6.
A synthetic approach to the C-terminal macrocycle of asperipin-2a is presented. Two epimers were prepared, possessing R- and S-configurations at the β-position of Tyr. Comparison of NMR data of the natural product with these isomers and X-ray crystallographic data for one macrocycle support assignment of the 2 S,3 S -configuration of Tyr. Key steps in the synthesis include a stereoselective benzylic oxidation of the tyrosine residue and Lewis-acid-catalyzed ring opening of the subsequently generated aziridine.
本文介绍了一种合成曲霉青霉素-2a C端大环的方法。制备了两个差向异构体，在Tyr的β位具有R-和S-构型。将天然产物的NMR数据与这些异构体进行比较，并对一个大环进行X射线晶体学数据，支持了Tyr的2S,3S-构型的归属。合成中的关键步骤包括酪氨酸残基的立体选择性苄基氧化和随后生成的氮丙啶的路易斯酸催化开环。
